Image measurement method and image measurement system

Abstract

An image measurement method for performing shape measurement of a component in which measurement points associated with identifiers are set includes: a first step of capturing images of the component to obtain measurement images; a second step of obtaining correspondence data in which the identifiers of the measurement points are associated with the measurement image; a third step of counting the number of measurement images associated with the identifier of each measurement point based on the correspondence data; a fourth step of calculating an evaluation point for each measurement image based on evaluation parameters including the number of measurement images; a fifth step of selecting and removing measurement images based on the calculated evaluation points; and a sixth step of performing the shape measurement of the component by using the measurement images other than the removed measurement images.

1 . An image measurement method for capturing images of components that are manufactured under an identical standard to perform shape measurement of the components, the shape measurement being performed for each of the components, a plurality of measurement points being set at preset positions of the component, the plurality of measurement points being associated with a plurality of identifiers,
 the image measurement method comprising:   capturing images of the component to obtain measurement images;   obtaining measurement points included in each obtained measurement image and obtaining correspondence data in which the identifiers of the measurement points are associated with the measurement image;   counting the number of measurement images associated with the identifier of each measurement point based on the obtained correspondence data;   calculating an evaluation point for each measurement image based on evaluation parameters including the number of measurement images associated with the identifier;   selecting and removing measurement images based on the calculated evaluation points; and   performing the shape measurement of the component by using the measurement images other than the removed measurement images.   
     
     
         2 . The image measurement method according to  claim 1 , wherein
 the evaluation point of the measurement image is calculated using an evaluation formula including the evaluation parameters,   the evaluation formula is weighted to lower the evaluation point when the number of measurement images associated with the identifier of each measurement point is small, and   the evaluation formula is weighted to raise the evaluation point when the number of measurement images associated with the identifier of each measurement point is large.   
     
     
         3 . The image measurement method according to  claim 2 , wherein the evaluation parameters of the evaluation formula include a photographing condition of the measurement image associated with the identifier of the measurement point. 
     
     
         4 . The image measurement method according to  claim 1 , further comprising:
 evaluating measurement accuracy of the shape measurement and determining whether the measurement accuracy is equal to or higher than predetermined measurement accuracy; and   setting, when the measurement accuracy is determined to be equal to or higher than the predetermined measurement accuracy, that the removed measurement images are not adopted in performing the shape measurement at the next sixth step.   
     
     
         5 . The image measurement method according to  claim 4 , further comprising restoring, when the measurement accuracy is determined to be lower than the predetermined measurement accuracy, the removed measurement images, wherein
 performing the shape measurement includes using the measurement images including the restored measurement images to perform the shape measurement.   
     
     
         6 . The image measurement method according to  claim 5 , wherein restoring the removed measurement images includes restoring the measurement images in decreasing order of the number of measurement points included in the measurement image, based on the correspondence data. 
     
     
         7 . The image measurement method according to  claim 1 , further comprising causing a display unit to display a display screen on which a result of photographing the component is displayed, wherein
 the display screen displays a component model in which the component is modeled, and displays a measurement point model of the measurement points set in the component model, and   causing the display unit to display the display screen includes displaying the numbers of measurement images and the measurement point model in association with each other in the display screen, based on the correspondence data.   
     
     
         8 . The image measurement method according to  claim 1 , further comprising changing, based on the number of measurement images associated with the identifier of each measurement point, photographing conditions for the measurement points of the component, wherein
 capturing images of the component includes capturing images of the component based on the changed photographing conditions changed at the eleventh step.   
     
     
         9 . An image measurement system that captures images of components that are manufactured under an identical standard to perform shape measurement of the components, the shape measurement being performed for each of the components, a plurality of measurement points being set at preset positions of the component, the plurality of measurement points being associated with a plurality of identifiers,
 the image measurement system comprising:   an image capturing device that captures the images of the component;   a moving unit that moves the image capturing device; and   a control unit that obtains the measurement images captured by the image capturing device and performs the shape measurement of the components, wherein   the control unit performs:
 capturing images of the component to obtain measurement images; 
 obtaining measurement points included in each obtained measurement image and obtaining correspondence data in which the identifiers of the measurement points are associated with the measurement image; 
 counting the number of measurement images associated with the identifier of each measurement point based on the obtained correspondence data; 
 calculating an evaluation point for each measurement image based on evaluation parameters including the number of measurement images associated with the identifier; 
 selecting and removing measurement images based on the calculated evaluation points; and 
 performing the shape measurement of the component by using the measurement images other than the removed measurement images.